most people cant handle taking in all the information that is thrown at them on their screen while they play. let along be able to actually understand that information then figure out how to use it and put it into a plan. and then communicate it effectively to their teammates.
This is why even in pro play today a good shot caller is worth their weight in gold.
Most players know what their champ does have a general idea of what other champs do.
Understand they need gold and to push towers to kill the enemy base.
They dont understand. match ups. cdrs. runes. cooldowns. builds. items. macro play. wave control. micro play. orb walking. attack moving. warding. vision control. objective control. level advantages. item spikes. ect ect on and on